I decided not to follow a pre-made plan for my marathon training due to several factors. First, I don't run as often as most plans require. I don't have the time or a safe place to run from my house. This week I only ran once during the week! Also, as a teacher I knew that a lot of my training would happen over the summer. I added miles months earlier than many plans require. Most importantly, I can be a little fanatical when it comes to following a plan. If I have to miss a run that's already on the calendar I feel like I've somehow failed. Yes, I know this isn't actually failure, but that's where my brain goes.
So instead of following a plan, I've set monthly mileage goals and weekly long run requirements. I've kept this up since July and it's worked well. In July, I had to run (or elliptical, but that's another story altogether) 100 miles. For August and September, the goal is 120 miles per month. I made it for August, but just barely. September's off to a better start. October's goal is 100 miles, and the race is Saturday, October 16.
For long runs, I add two miles every other week. On the off weeks, I run 12 or 14. This means that next week I'll run 20, and two weeks after that I'll run 22. I haven't decided if I'll make it all the way to 24 or not. At this point I doubt it.
This unconventional training plan has worked so far; I'm injury-free and the long runs haven't killed me or my desire to run. I don't know if I'll finish the race in under four hours, but it's my goal!